There are a number of medical tests that require the monitoring of a patient, and in particular the monitoring of a mother and the fetus during pregnancy, with an ultrasound transducer, e.g. obtaining the fetal heartbeat, as well as a number of other conditions that cannot be observed directly.
In use, a coupling gel is applied to the transducer face and the transducer is then moved over the area of the patient where the best data is obtained. The data is typically observed on a monitor, and/or is stored on hard storage media.
If data is to be obtained over a long period of time, some means of holding the ultrasound transducer in place is required. The present means of maintaining the ultrasound transducer on the patient is by using an encircling abdominal belt, as is commonly used for holding a tocodynamometer in place during the measurement of contractions.
Such belts when used with the ultrasound transducer are difficult to keep in place. The ultrasound transducer must be held in a desired position once the belt has been tightened and locked. Since the surface of the maternal abdomen is not uniform or flat, it is sometimes difficult to fix the orientation of the ultrasound transducer at the optimum angle to obtain the fetal heartbeat. Because the tension of the belt system holds the transducer face essentially parallel to the maternal abdomen wall, it is sometimes difficult to obtain the required data, and it becomes necessary to change this parallel orientation by angulating the transducer face. In the absence of a mechanical method to do this clinically, this is frequently done by inserting small pieces of material, such as wadded paper to achieve this end. Further, the abdomen of the pregnant woman does not maintain a constant shape during the testing period. The movement of the fetus, as well as contractions, cause the shape of the abdomen to change. This alters the pressure on the belt, causing it to slip and change position, thereby also causing the ultrasound transducer to change its position. The required data is thus frequently lost or its reliability is compromised. The instability of the procedure demands constant checking by the nursing and medical staff to make sure that the ultrasound transducer has not moved significantly.
In addition, with the belt system, it is not possible to have the patient move much during the time that data is being recorded, otherwise the position and/or orientation of the ultrasound transducer will be changed and the data compromised, or lost entirely. Even turning over in bed can cause total loss of data. However, during some tests, it is important to have the patient not only move, but also exercise while recording fetal heart rate data. Heretofore, there has been no apparatus that would permit the patient to exercise and still obtain good quality fetal heart rate recordings.